1. Field of the Invention
This invention relates to a ceramic burner for the combustion of a gas/air mixture. Such burner can be located in the lower portion of a combustion chamber of a hot blast stove. The burner possesses inlet pipe-sections for gas and combustion air, which open into the combustion chamber, together with associated gas and air chambers, which merge into gas-slots and air-slots having an elongated horizontal cross-section, these slots being located one besides another, running vertically, and being separated one from another. Above the gas- and air-slots, the two media are mixed in one or more distributor-courses, and are burnt at the crown of the burner.
2. Discussion of Prior Art
Ceramic burners of this generic type are known. See for example, German Auslegeschrift No. 1,290,285 and German Offenlegungsschrift No. 1,526,027. They are employed, in particular, in hot blast stoves for blast furnaces, in order to generate the hot blast which is required for operating the blast furnace. These burners enable effective and thorough mixing of the media (gases) to be achieved, and enable the media to be uniformly distributed. A starting-up procedure is necessary when bringing a hot blast stove into service in order to heat up the cold blast stove. Due to a limited range of control, this starting-up procedure cannot be carried out with the known ceramic burners. A cold hot blast stove, which is equipped with a ceramic burner of the type described above, must accordingly be started-up with the aid of a separate auxiliary burner which is generally a mechanically operated burner with an appropriate control range. After reaching the starting-up temperature of approximately 500.degree.-700.degree. C. the auxiliary burner is removed. The further heating up of the hot blast stove can then be continued by means of the built-in ceramic burner.
In the event of plant shutdowns lasting for less than three months, it is advantageous to avoid allowing the hot blast stove to completely cool down to the cold state. Instead, it is maintained at a temperature of approximately 600.degree. C. The ceramic burners of the known type are likewise unsuitable for carrying out this so-called "standby" operation. This applies, in particular, if, in the event of a plant shutdown, the supply of lean gas (blast furnace waste gas) from the blast furnace also ceases, and only rich gas (natural gas, coke-oven gas) is available for the "stand-by" operation. Up to the present time, it was accordingly necessary to employ an additional temperature-maintaining burner for the "stand-by" operation, the erection and dismantling of this burner representing a considerable expense.
It is an object of this invention, therefore, to provide a ceramic burner which is unencumbered by the drawbacks of the previous burners, in terms of their controllability, and avoids the disadvantages of the known burner in respect of their inability to economically function during a "stand-by" operation, especially with regard to the erection and dismantling of separate auxiliary burners.